Art of annealing metal castings



UNITED TATES PATENT 'oFFIC DAVID ivr envrosn, or NEWARK, NEW JERSEY.

ART OF ANNEALING METAL oAs'rrnGs.

No Drawing.

To all whom it may concern: I

Be it known that I, DAVID MAoIN'rosH, of Newark, in the county of Essex andState of New Jersey, have invented a certain new and useful Improvement in the Art of Annealing Metal Castings, of which improvement the following is a speclficatlon.

articles in annealing the same to produce malleable castings, in which operation, under the high temperature, some ofthe oxygen of the'ferric oXid combines with carbon from the casting, thus forming carbonic oXid, which passes off as gas, and effects the desired decarbonization of the outer-portion of the casting. Under the high temperature, however, the packing material fuses more or less with the castings, so that after cooling, many of the castings are found stuck together in a mass, which can be separatedonly with difficulty. It then requires considerable time and effort to break the masses apart, separate and clean up" the castings, all of which causes delay and in-- creases the cost of manufacture. Those obections are overcome by means of my 31mproved packing material, which does not fuse or stick to the malleable castings, but

falls freely away from the same when taken out after cooling. leaving the castings perfectly clean.

According to the practice of my inventhe iron castings to be annealed are cium carbonate, preferably in the form of ground shells, such as oyster shells, the same being packed in layers between the layers of' castings which are embedded therein, so that there is a large'amount of the calclum car- Specification of Letters Patent.

high temperature for a period oftime, and

PatentedOct. 26, 1920.

Application filed Jul ii, 1919. serialno. 310,128.

bonate relative to the iron. The loaded boxes are then placed in the oven and heated to a high temperature of about 1600 to 1700 degrees Fahrenheit, and held at that temperature for a certain period of time, usually about three or four hours, after which they are gradually cooled and then taken out. I

When the boxes are emptied, the castings readily separate from the packing material, which falls away, leaving the clean castings malleable castings are also found to be thoroughly annealed and may be'pounded and with no tendency to stick together. The

bent without breaking, thus showing the efli I ciency of the process.

The packing material of oyster shells'm'ay also be. used over; again for several times,

and is then reduced to quick lime, CaO,

which is itself a valuable by-product, and may be sold for various purposes.

My improvement has the advantage of greatly reducing the time and expense involved in making malleable iron castings, as the packing material employed, 2'. 6., oyster shells, is very cheap, being now thrown away in large quantities at wharves and markets, where they can be had for nothing by simply carting them away. I Having nowdescribed my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of annealing castings, which consists in embedding said castings in a packing material consisting wholly of calcium carbonate in granular form, and in a large quantity relative to the amount'of iron, heating the same to a high tempera-l ture for a periodof time, and then gradually cooling the same.

'2. The process of annealing castings,

which consists in embedding said castings in ground. oyster shells, there being a large amount of said. packing material relative to the amount of 1ron, heat1ng the same to a navmmcinrosni I 

